US4955484A - Device for separating hard objects, such as stones, from a stream of wood - Google Patents

Device for separating hard objects, such as stones, from a stream of wood Download PDF

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Publication number
US4955484A
US4955484A US07/314,541 US31454189A US4955484A US 4955484 A US4955484 A US 4955484A US 31454189 A US31454189 A US 31454189A US 4955484 A US4955484 A US 4955484A
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United States
Prior art keywords
wood
logs
blocks
separation
stream
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Expired - Lifetime
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US07/314,541
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English (en)
Inventor
Kari Rintala
Jyrki Paarma
Mikko Sissala
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Andritz Patentverwaltungs GmbH
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Kone Corp
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Assigned to KONE OY reassignment KONE OY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SISSALA, MIKKO, PAARMA, JYRKI, RINTALA, KARI
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Assigned to ANDRITZ-PATENTVERWALTUNGS-GESELLSCHAFT M.B.H. reassignment ANDRITZ-PATENTVERWALTUNGS-GESELLSCHAFT M.B.H. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: OY, KONE
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
    • B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
    • B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
    • B07C5/34—Sorting according to other particular properties

Definitions

  • This invention relates to a device for separating hard objects, such as stones, from a stream of wood in an apparatus conveying or manipulating logs or blocks of wood.
  • conveyors are generally used for the transportation of logs and blocks of wood.
  • stones, metal objects or other hard objects carried along with the wood stream on the conveyors get into a processing machine, e.g. a chipper, this often leads to a shutdown in production and necessitates repairs. Therefore, it is important that hard objects be removed from the stream of wood prior to further processing thereof.
  • Furruginous objects carried with the wood can be detected, e.g. by means of metal detectors.
  • a common method has been to use a stone catcher built in connection with the conveyor.
  • the stone catcher is a basin filled with water, over which the wood stream is passed, so that the stones, having a higher specific gravity, sink to the bottom of the basin.
  • German patent application DE No. 2946797A1 proposes an apparatus which classifies small objects on the basis of the sound they produce and places them in different containers. The small objects fall along a groove-like track onto a plate and the sound thus produced is compared to that caused by a small reference object. This sound is utilized by a comparator unit which controls a small actuator which guides the falling small object into a given container.
  • this prior system cannot be used for the separation of stones from a stream of logs and blocks of wood.
  • An object of the present invention is to provide a device which enables the separation of stones from a stream of wood on a conveyor without the use of a water-operated stone catcher.
  • the device of the invention mainly consists of the conveyor, which is required in any case, to which has been added only the equipment needed for the detection and removal of stones.
  • the invention provides a device for separating hard objects from a stream of wood in an apparatus for conveying or manipulating logs or blocks of wood, which comprises: a conveyor section, at least one transducer capable of registering acoustic vibrations, a control unit connected to said at least one transducer by means of which hard objects conveyed along with the wood stream can be detected on the basis of the vibration signals they generate, and an exit gear incorporated in the apparatus for conveying or manipulating tree trunks and controlled by said control unit, so that said hard objects can fall down from the steam of wood passing through the apparatus.
  • FIG. 1 shows graphically the forms of force impulses generated when a hard object hits a soft object (A) and when a hard object hits another hard object (B);
  • FIG. 2 shows graphically the frequency distribution (power spectral density) of force impulses as shown in FIG. 1, curve A representing a collision of a hard object and a soft object, and curve B representing a collision of two hard objects;
  • FIG. 3 depicts graphically the amplitude/frequency distribution of the vibration generated in a steel structure in an apparatus when hit by a wooden object A and, correspondingly, when hit by a hard object B;
  • FIG. 4 is a diagrammatic perspective view of an embodiment of the device of the invention.
  • FIG. 5 is a block diagram showing schematically an embodiment of a signal processing unit.
  • the force impulse generated is of a "soft" form and has a relatively long duration, as indicated by curve A in FIG. 1.
  • curve A in FIG. 2 the lower frequencies of vibration have larger amplitude values than the higher frequencies, as indicated by curve A in FIG. 3.
  • the vibration frequencies generated by impacts from wooden objects are typical natural frequencies of large structural assemblies.
  • the resulting force impulse is of a "sharp" form and is relatively short in duration, as indicated by curve B in FIG. 1.
  • the range of vibration frequencies in the collision impulse is extended to higher frequencies, as shown by curve B in FIG. 2.
  • the amplitude distribution contains more high frequencies than in the case of a collision of wood and metal.
  • FIG. 4 shows part of a log conveyor on which a stone or other hard object 4 is carried along with logs and blocks of wood 1.
  • the impacts resulting from the stone hitting the rollers cause vibrations and sounds.
  • These vibrations are identified by vibration transducers 6 attached to steel structure 5 of the apparatus and the vibration signals are processed by a measurement and control unit 7.
  • the control unit 7 sends a command to an actuator 11 of an exit door 12, which is disposed between the rollers 3 at a point further downstream on the conveyor.
  • the actuator 11 opens the exit door 12, so that the stone 4 will fall down into a space below the conveyor.
  • the measuring point of one or more of the vibration transducer 6 used with the device of the invention may also be a bearing, the housing of a bearing, a supporting structure, a conveyor wall, or a plate, roller, bar, disc or similar metal object specifically designed for this purpose and preferably insulated against vibratory influences from the environment.
  • the vibration transducer 6 used in the device of the invention may also consist of a microphone, or the device may be provided with both a microphone and a vibration transducer 6. Via the medium of air, the microphone measures the sound generated by the mechanical vibration of the conveyor.
  • the device of the invention may be covered with sound insulation to reduce environmental background noise when a microphone is used for the detection of vibration.
  • FIG. 5 shows a block diagram of the signal processing unit used in an embodiment of the device of the invention.
  • the measurement and control unit 7 comprises an amplifier 8, a filter 9 and a unit 10 for measurement of the r.m.s. value.
  • the signal provided by the transducer 6 is amplified by the adjustable amplifier 8, whose output signal is filtered by a bandpass filter 9 to achieve a better signal-to-noise ratio.
  • the filter 9 is so tuned that only vibrations caused by the impacts of hard objects are passed through, while vibrations caused by the impacts of wooden objects are not passed through at all or are considerably attenuated when they reach the next stage 10, where the r.m.s. value of the amplitude of the vibration signal is measured.
  • the unit 10 measuring the r.m.s. value measures the signal strength in terms of an average value suitably obtained or a quantity proportional thereto, e.g. the r.m.s. value.
  • the unit 10 measuring the r.m.s. value sends a control signal to the actuator 11, which then opens the exit door 12 to remove the stone 4.

Landscapes

  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
  • Jigging Conveyors (AREA)
  • Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
US07/314,541 1988-02-29 1989-02-23 Device for separating hard objects, such as stones, from a stream of wood Expired - Lifetime US4955484A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI880930A FI79955C (fi) 1988-02-29 1988-02-29 Anordning foer avskiljning av haorda foeremaol, saosom stenar fraon en stroem av traedstammar.
FI880930 1988-02-29

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US07/580,280 Continuation-In-Part US5082118A (en) 1988-02-29 1990-09-10 Device for separating hard objects, such as stones, from a stream of wood

Publications (1)

Publication Number Publication Date
US4955484A true US4955484A (en) 1990-09-11

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ID=8525996

Family Applications (2)

Application Number Title Priority Date Filing Date
US07/314,541 Expired - Lifetime US4955484A (en) 1988-02-29 1989-02-23 Device for separating hard objects, such as stones, from a stream of wood
US07/580,280 Expired - Lifetime US5082118A (en) 1988-02-29 1990-09-10 Device for separating hard objects, such as stones, from a stream of wood

Family Applications After (1)

Application Number Title Priority Date Filing Date
US07/580,280 Expired - Lifetime US5082118A (en) 1988-02-29 1990-09-10 Device for separating hard objects, such as stones, from a stream of wood

Country Status (10)

Country Link
US (2) US4955484A (lt)
AT (1) AT400536B (lt)
CA (1) CA1321167C (lt)
DE (1) DE3906089C2 (lt)
FI (1) FI79955C (lt)
LT (1) LT3399B (lt)
LV (1) LV11013B (lt)
NO (1) NO177582C (lt)
RU (1) RU1806025C (lt)
SE (1) SE466583B (lt)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5082118A (en) * 1988-02-29 1992-01-21 Kone Oy Device for separating hard objects, such as stones, from a stream of wood
ES2112118A1 (es) * 1994-03-28 1998-03-16 Ikerlan S Coop Aparato para separar las piedras de las patatas en una cosechadora de patatas.
US5981892A (en) * 1996-12-06 1999-11-09 Fmc Corporation Food handling conveyor apparatus having sound detection means
US20050173858A1 (en) * 2004-02-05 2005-08-11 Temler Jan S. Automatic conveyor slot closure
US20060277883A1 (en) * 2005-06-10 2006-12-14 Berger John G Acoustic stone detection for a feederhouse on an agricultural combine
US20150285927A1 (en) * 2008-06-17 2015-10-08 Weir-Jones Engineering Consultants Ltd. System and method for detecting rock fall
CN113245213A (zh) * 2021-07-13 2021-08-13 深圳贝标新材料科技有限公司 一种基于互联网的防水板材分选监管系统

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10158728A1 (de) * 2001-11-30 2003-06-18 Stadler Anlagenbau Gmbh Verfahren zum Erkennen von Stör- und/oder Schwerstoffen
US6601372B1 (en) * 2002-02-22 2003-08-05 New Holland North America, Inc. Stone detection method and apparatus for harvester
DE10309120A1 (de) * 2003-02-28 2004-09-16 Stefan Corbach Verfahren und Vorrichtung zur Trennung von unsortierten Gemischen aus Metallteilen unterschiedlicher Metalle bzw. deren Legierungen
US7520111B2 (en) * 2005-06-10 2009-04-21 Cnh America Llc Stone detection method and apparatus for a harvester
AT505224B1 (de) * 2007-05-09 2009-04-15 Peter Winkl Vorrichtung zum fullen von paletten mit holzstucken
SI23176A (sl) 2009-10-21 2011-04-29 Winkl Peter Mobilna naprava za zlaganje polen v paleto s stranicami
EP2581332B1 (en) 2011-10-12 2015-12-02 Peter Winkl Procedure and mobile device for stacking wooden logs onto a pallet with raised sides
CN110980190A (zh) * 2019-11-11 2020-04-10 无锡纳净科技有限公司 一种可更换图像采集单元的智能检测设备

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2208202A (en) * 1938-05-25 1940-07-16 Electrical Res Prod Inc Can inspection system
US2593089A (en) * 1949-08-22 1952-04-15 Barry Leonard Dodge Roller conveyer construction
US3394806A (en) * 1966-06-07 1968-07-30 Sona Tronic Company Inc Vibration actuated sorting device
GB1145702A (en) * 1964-12-31 1969-03-19 Phoenix Timber Company Ltd Improvements relating to the testing and grading of timber
US3559805A (en) * 1968-07-02 1971-02-02 Patricia A Cragg Stone and rock removing device
US4147620A (en) * 1977-06-15 1979-04-03 Black Clawson Inc. Method and apparatus for sorting contaminant material from processing material
US4309903A (en) * 1979-12-26 1982-01-12 The Regents Of The University Of California Method and apparatus for analyzing selected material properties with magnetomechanical acoustic emissions
US4602716A (en) * 1982-02-23 1986-07-29 Licencia Talalmanyokat Ertekesito Vallalat Process for determining the soundness of sowing seeds and their soundness-dependent germinative ability, and apparatus for carrying out the process

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4205233A (en) * 1978-11-22 1980-05-27 Raytheon Company Automatic bucky lock
US4523682A (en) * 1982-05-19 1985-06-18 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Acoustic particle separation
FI79955C (fi) * 1988-02-29 1990-04-10 Kone Oy Anordning foer avskiljning av haorda foeremaol, saosom stenar fraon en stroem av traedstammar.

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2208202A (en) * 1938-05-25 1940-07-16 Electrical Res Prod Inc Can inspection system
US2593089A (en) * 1949-08-22 1952-04-15 Barry Leonard Dodge Roller conveyer construction
GB1145702A (en) * 1964-12-31 1969-03-19 Phoenix Timber Company Ltd Improvements relating to the testing and grading of timber
US3394806A (en) * 1966-06-07 1968-07-30 Sona Tronic Company Inc Vibration actuated sorting device
US3559805A (en) * 1968-07-02 1971-02-02 Patricia A Cragg Stone and rock removing device
US4147620A (en) * 1977-06-15 1979-04-03 Black Clawson Inc. Method and apparatus for sorting contaminant material from processing material
US4309903A (en) * 1979-12-26 1982-01-12 The Regents Of The University Of California Method and apparatus for analyzing selected material properties with magnetomechanical acoustic emissions
US4602716A (en) * 1982-02-23 1986-07-29 Licencia Talalmanyokat Ertekesito Vallalat Process for determining the soundness of sowing seeds and their soundness-dependent germinative ability, and apparatus for carrying out the process

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5082118A (en) * 1988-02-29 1992-01-21 Kone Oy Device for separating hard objects, such as stones, from a stream of wood
ES2112118A1 (es) * 1994-03-28 1998-03-16 Ikerlan S Coop Aparato para separar las piedras de las patatas en una cosechadora de patatas.
US5981892A (en) * 1996-12-06 1999-11-09 Fmc Corporation Food handling conveyor apparatus having sound detection means
US20050173858A1 (en) * 2004-02-05 2005-08-11 Temler Jan S. Automatic conveyor slot closure
US7413088B2 (en) * 2004-02-05 2008-08-19 International Paper Company Automatic conveyor slot closure
US20060277883A1 (en) * 2005-06-10 2006-12-14 Berger John G Acoustic stone detection for a feederhouse on an agricultural combine
US20150285927A1 (en) * 2008-06-17 2015-10-08 Weir-Jones Engineering Consultants Ltd. System and method for detecting rock fall
CN113245213A (zh) * 2021-07-13 2021-08-13 深圳贝标新材料科技有限公司 一种基于互联网的防水板材分选监管系统
CN113245213B (zh) * 2021-07-13 2021-09-17 深圳贝标新材料科技有限公司 一种基于互联网的防水板材分选监管系统

Also Published As

Publication number Publication date
NO177582C (no) 1995-10-18
FI79955B (fi) 1989-12-29
FI79955C (fi) 1990-04-10
FI880930A0 (fi) 1988-02-29
AT400536B (de) 1996-01-25
DE3906089C2 (de) 1995-06-01
ATA41789A (de) 1995-06-15
RU1806025C (ru) 1993-03-30
LV11013A (lv) 1996-02-20
NO177582B (no) 1995-07-10
DE3906089A1 (de) 1989-09-07
LTIP694A (en) 1995-01-31
SE8900676D0 (sv) 1989-02-27
SE8900676L (sv) 1989-08-30
SE466583B (sv) 1992-03-09
FI880930A7 (fi) 1989-08-30
NO890743D0 (no) 1989-02-22
CA1321167C (en) 1993-08-10
LV11013B (en) 1996-04-20
NO890743L (no) 1989-08-30
LT3399B (en) 1995-09-25
US5082118A (en) 1992-01-21

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